A dewaxing solvent, its application and a new method for dewaxing rose essential oil crude oil

Abstract

The present application relates to the technical field of plant oil refining, and discloses a dewaxing solvent and application thereof and a novel method for dewaxing rose essential oil crude oil. The dewaxing solvent comprises one or more of polar organic solvents, non-polar organic solvents and deionized water. The method comprises the following steps: one or more of polar organic solvents, non-polar organic solvents and deionized water are prepared into a novel dewaxing solvent according to a certain proportion, the dewaxing solvent is added into rose essential oil crude oil, and after uniform stirring at room temperature, the upper oil-like substance is collected as rose wax, and the lower rose essential oil clear liquid is subjected to vacuum concentration to remove the dewaxing solvent, so that rose essential oil with wax removed is obtained. The method has the characteristics of simple operation, short time, high efficiency and no introduction of toxic and harmful substances, has obvious dewaxing effect, and the total wax residue rate of rose essential oil after dewaxing is not higher than 9.83%, the rose essential oil after dewaxing is clearer and more transparent, has higher volatility, and has more pure aroma, and the effect is better than that of the conventional low-temperature stirring crystallization dewaxing method, and the method is convenient for industrialized production.

Description

Technical Field

[0001] This invention relates to the field of vegetable oil refining technology, and discloses a dewaxing solvent and its application, as well as a new method for dewaxing crude rose essential oil. Background Technology

[0002] Roses, belonging to the genus Rosa in the family Rosaceae, are deciduous, bushy shrubs and one of the world's most famous flowers. Roses are sweet and warm in nature, possessing various medicinal and health benefits, including promoting qi circulation, relieving depression, soothing the liver, regulating qi, promoting blood circulation, and astringing. They are woody plants that integrate medicinal, edible, aesthetic, and landscaping uses. The primary use of roses is for extracting essential oil, which contains various fragrant substances that give roses their elegant, soft, and delicate fragrance. Rose essential oil is a high-grade and expensive fragrance with moisturizing, antibacterial, and anti-aging effects. It also has stress-relieving, sleep-improving, and anti-depressant properties, making it widely used in food, medicine, cosmetics, and high-end tobacco flavoring. Due to its high price, rose essential oil is known as "liquid gold" and has immense economic value.

[0003] Rose essential oil can be extracted using methods such as steam distillation, organic solvent extraction, supercritical CO2 fluid extraction, and molecular distillation. Among these methods, steam distillation is widely used in rose essential oil production due to its advantages of low equipment investment costs, simple operation, and ease of scale-up. However, regardless of the extraction process, crude rose oil extracted from rose petals contains a large amount of wax, requiring dewaxing during subsequent refining. Wax in essential oils is a high-grade aliphatic hydrocarbon, which can increase the cloud point, decrease transparency, hinder the volatilization of aroma components, and reduce the quality of rose essential oil. International standards clearly define the wax content of rose essential oil. In short, high-quality rose essential oil should be dewaxed. Dewaxing separates the oil and wax in the extracted crude rose oil, thereby removing the wax to obtain purified rose oil.

[0004] Existing technology CN 104140889 A discloses a method for preparing rose absolute, which involves dissolving rose extract extracted with organic solvents in anhydrous ethanol or 95% ethanol, cooling to 20-25°C, and soaking for 8-10 hours to allow wax crystallization. The undissolved original wax is then filtered off to obtain a rose solvent filtrate. This filtrate is then further frozen at -5 to -20°C for 15-20 hours to allow the wax to recrystallize. Finally, it is centrifuged at 8000-10000 r / min for 10-15 minutes to allow the wax to settle, resulting in rose wax and a rose supernatant. The rose supernatant, after wax removal, is then concentrated to obtain rose absolute. However, this conventional dewaxing method involving multiple cooling, crystallization, sedimentation, and final centrifugation or filtration is complex, time-consuming, and energy-intensive. Furthermore, during the cooling and crystallization process, the wax also encapsulates aromatic components from the essential oil, resulting in significant loss of these components and unsatisfactory results. Therefore, it is necessary to find a simple, fast, low-cost, low-energy, and efficient method to remove wax from crude rose essential oil. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a dewaxing solvent that can be used in the dewaxing of crude rose essential oil with good dewaxing effect.

[0006] Another object of the present invention is to provide the application of the above-mentioned dewaxing solvent in the dewaxing of crude rose essential oil, and to provide a new method for removing wax from crude rose essential oil using the dewaxing solvent.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A dewaxing solvent includes one or more of a polar organic solvent, a non-polar organic solvent, and deionized water, which can be directly mixed during preparation.

[0009] Preferably, the volume percentage of polar organic solvent, non-polar organic solvent and deionized water in the dewaxing solvent is 10:0-5:1-10.

[0010] Preferably, the polar organic solvent is ethanol and / or isopropanol.

[0011] Preferably, when the polar organic solvent is ethanol and n-propanol, the volume ratio of the two is 1:0.1-2.

[0012] Preferably, the nonpolar organic solvent is one or a mixture of several of the following: n-hexane, cyclohexane, n-pentane, cyclopentane, and petroleum ether.

[0013] Preferably, the nonpolar organic solvent can be a combination of n-hexane and cyclopentane, or a combination of cyclohexane, n-pentane, and petroleum ether.

[0014] When the nonpolar organic solvent is a combination of n-hexane and cyclopentane, the preferred volume ratio of the two is 10:3.

[0015] When the nonpolar organic solvent is cyclohexane, n-pentane, and petroleum ether, the volume ratio of the three is 7:2:5.

[0016] When the dewaxing solvent described in this invention is applied to the dewaxing process of crude rose essential oil, the dewaxing effect is superior to that of conventional low-temperature crystallization dewaxing methods. Based on this, this invention provides the application of the dewaxing solvent in the dewaxing of crude rose essential oil and / or in the preparation of dewaxed crude rose essential oil products.

[0017] According to the application, the present invention also provides a new method for dewaxing crude rose essential oil. Under normal temperature conditions, the dewaxing solvent described in the present invention is added to the crude rose essential oil and mixed evenly. Then, it is allowed to stand and the upper layer of rose wax and the lower layer of dewaxed rose essential oil are separated.

[0018] The ambient temperature is 20-30℃, preferably 25℃; the settling time is 5-60 minutes.

[0019] min.

[0020] Preferably, the amount of the dewaxing solvent added accounts for 10-500% of the total volume of crude rose essential oil.

[0021] To further improve the dewaxing effect, the method described in this invention further performs vacuum concentration on the dewaxed rose essential oil after obtaining the clear liquid, resulting in dewaxed rose essential oil with a citronellol content of not less than 34.82%, a nerol content of not less than 6.37%, and a geraniol content of not less than 15.57%. The total wax residue rate of the dewaxed rose essential oil is not higher than 9.83%, with a heptadecane content of not more than 1.13%, a nonadecane content of not more than 7.12%, and a dodecane content of not more than 1.58%.

[0022] The vacuum concentration method is rotary evaporation, and the rotary evaporation temperature is 25-35℃, and the vacuum degree is -0.09 to -0.1 MPa.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The present invention provides a dewaxing solvent composed of a polar organic solvent, a non-polar organic solvent and deionized water, which can be applied to the dewaxing process of crude rose essential oil, so that the dewaxed rose essential oil has a low wax residue rate, avoids the loss and waste of aromatic components in the essential oil, makes the rose essential oil clearer and more transparent, more volatile, and has a purer aroma, and the effect is better than the conventional low temperature stirring crystallization dewaxing method.

[0025] (2) The present invention has the advantages of simple operation, short time, low cost, low energy consumption and high efficiency, which makes it easy to scale up industrial production. Attached image description:

[0026] Figure 1 The diagram shown is a flowchart of the process for removing wax from crude rose essential oil according to an embodiment of the present invention.

[0027] Figure 2 The image shows the GC detection spectra of rose wax and dewaxed rose essential oil obtained in Example 1 of the present invention; where A represents crude rose essential oil, B represents dewaxed rose essential oil, and C represents separated rose wax. Detailed implementation method:

[0028] This invention discloses a dewaxing solvent and its application, as well as a novel method for dewaxing crude rose essential oil. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired results. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are included in this invention. The dewaxing solvent and its application, as well as the novel method for dewaxing crude rose essential oil, described in this invention have been illustrated through preferred embodiments. Those skilled in the art can clearly modify or appropriately alter and combine the dewaxing solvent and its application, as well as the novel method for dewaxing crude rose essential oil, without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0029] The following provides further explanation of the dewaxing solvent provided by this invention, its application, and a new method for dewaxing crude rose essential oil.

[0030] Example 1

[0031] This embodiment provides a dewaxing solvent and its application, as well as a new method for dewaxing crude rose essential oil. The specific steps are as follows:

[0032] (1) Preparation of dewaxing solvent:

[0033] A mixture of polar organic solvents, non-polar organic solvents, and deionized water in a volume ratio of 10:0.1:3 is used as a dewaxing solvent.

[0034] Among them, the mixed solvent of ethanol:isopropanol with a volume ratio of 1:0.5 is a polar organic solvent, and the mixed solvent of n-hexane:cyclopentane with a volume ratio of 10:3 is a non-polar organic solvent.

[0035] (2) A new method for dewaxing crude rose essential oil

[0036] At 25°C, the dewaxing solvent described in step (1) is added to the crude rose essential oil. The volume ratio of the dewaxing solvent to the crude rose essential oil is 1:1. The mixture is stirred evenly and then left to stand for 10 minutes to separate the upper layer of rose wax and the lower layer of dewaxed rose essential oil.

[0037] (3) Vacuum concentration of dewaxed rose essential oil solution

[0038] The dewaxed rose essential oil was concentrated by vacuum rotary evaporation at a temperature of 30°C and a vacuum of -0.095 MPa to obtain dewaxed rose essential oil containing 38.95% citronellol, 7.69% nerol, and 16.56% geraniol. The total wax residue of the dewaxed rose essential oil was 8.99%, with heptadecanes containing 0.93%, nonadecanes containing 6.85%, and heptadecanes not exceeding 1.21%.

[0039] Example 2

[0040] This embodiment provides a dewaxing solvent and its application, as well as a new method for dewaxing crude rose essential oil. The specific steps are as follows:

[0041] (1) Preparation of dewaxing solvent:

[0042] A mixture of polar organic solvents, non-polar organic solvents, and deionized water in a volume ratio of 10:0.1:3 is used as a dewaxing solvent.

[0043] Among them, the mixed solvent of ethanol:isopropanol with a volume ratio of 1:0.5 is a polar organic solvent, and the mixed solvent of cyclohexane:n-pentane:petroleum ether with a volume ratio of 7:2:5 is a non-polar organic solvent.

[0044] (2) A new method for dewaxing crude rose essential oil

[0045] At 25°C, the dewaxing solvent described in step (1) is added to the crude rose essential oil. The volume ratio of the dewaxing solvent to the crude rose essential oil is 1:1.5. The mixture is stirred evenly and then left to stand for 20 minutes to separate the upper layer of rose wax and the lower layer of dewaxed rose essential oil.

[0046] (3) Vacuum concentration of dewaxed rose essential oil solution

[0047] The dewaxed rose essential oil was concentrated by vacuum rotary evaporation at a temperature of 30°C and a vacuum of -0.09 MPa to obtain dewaxed rose essential oil containing 40.58% citronellol, 8.73% nerol, and 18.67% geraniol. The total wax residue of the dewaxed rose essential oil was 6.59%, with heptadecanes containing 0.82%, nonadecanes containing 4.76%, and heptadecanes containing 1.01%.

Claims

1. A dewaxing solvent for dewaxing crude rose essential oil, characterized in that, It consists of a polar organic solvent, a non-polar organic solvent, and deionized water, wherein: The volume ratio of the polar organic solvent, the non-polar organic solvent, and deionized water is 10:0.1:3; The polar organic solvent is a mixed solvent of ethanol and isopropanol in a volume ratio of 1:0.5; The nonpolar organic solvent is a mixed solvent composed of n-hexane and cyclopentane in a volume ratio of 10:3; When the dewaxing solvent is used to dewax crude rose essential oil, it is mixed with crude rose essential oil at a volume ratio of 1:1 at 25 ℃, and then allowed to stand for 10 minutes to achieve oil-wax separation.

2. A dewaxing solvent for dewaxing rose absolute crude oil, characterized by comprising, It consists of a polar organic solvent, a non-polar organic solvent, and deionized water, wherein: The volume ratio of the polar organic solvent, the non-polar organic solvent, and deionized water is 10:0.1:3; The polar organic solvent is a mixed solvent of ethanol and isopropanol in a volume ratio of 1:0.5; The nonpolar organic solvent is a mixed solvent composed of cyclohexane, n-pentane, and petroleum ether in a volume ratio of 7:2:5; When the dewaxing solvent is used to dewax crude rose essential oil, it is mixed with crude rose essential oil at a volume ratio of 1:1.5 at 25 ℃ and allowed to stand for 20 minutes to achieve oil-wax separation.

3. The application of the dewaxing solvent according to claim 1 or 2 in the dewaxing of crude rose essential oil.

4. The use of the dewaxing solvent according to claim 1 or 2 in the preparation of dewaxing rose essential oil products.

5. A method of dewaxing rose essential oil crude oil, characterized by, Includes the following steps: (a) At 25 °C, the dewaxing solvent of claim 1 is added to crude rose essential oil and mixed evenly; wherein the volume ratio of the dewaxing solvent to crude rose essential oil is 1:

1. (b) Let the mixture obtained in step (a) stand for 10 minutes to separate the upper layer of rose wax and the lower layer of dewaxed rose essential oil. (c) The lower layer of dewaxed rose essential oil obtained in step (b) is concentrated by rotary evaporation at 25-35℃ and vacuum degree -0.09~-0.1MPa to remove the dewaxing solvent and obtain dewaxed rose essential oil.

6. A method of dewaxing rose essential oil crude oil, characterized by, Includes the following steps: (a) At 25 °C, the dewaxing solvent of claim 2 is added to crude rose essential oil and mixed evenly; wherein the volume ratio of the dewaxing solvent to crude rose essential oil is 1:1.

5. (b) Let the mixture obtained in step (a) stand for 20 minutes to separate the upper layer of rose wax and the lower layer of dewaxed rose essential oil; (c) The lower layer of dewaxed rose essential oil obtained in step (b) is concentrated by rotary evaporation at 25-35℃ and vacuum degree -0.09~-0.1MPa to remove the dewaxing solvent and obtain dewaxed rose essential oil.

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